(Beraisa):Seven
things were created before the world - Torah, repentance, Gan Eden,
Gehinom, the Kisei ha'Kavod, the Beis ha'Mikdash, and the name of
Mashi'ach;(Translation from dafyomi.co.il)

Well, now thanks to a judge in Cocke Count, we know what that name was, and in case you thought it was Menachem, the correct answer is in fact Martin.

US judge changes baby's name from Messiah to Martin
The judge in Cocke County said the name Messiah could cause the boy difficulties if he grew up in a predominantly Christian area.
"It could put him at odds with a lot of people and at this point he has had no choice in what his name is," Judge Ballew said.
...
Instead the judge ruled that the baby was to be named Martin DeShawn McCullough, which includes both parents' last name.
"The word Messiah is a title and it's a title that has only been earned by one person and that one person is Jesus Christ," she said.
(Source: http://www.bbc.co.uk/news/world-us-canada-23665106
Hat Tip: Life in Israel)